The multilevel physical optics (MLPO) method is an effective method for performing the simulation of scattering patterns from a range of frequencies and aspect angles. However, the number of plane patches used to discretize the surfaces of the scatterers will increase with the frequency. Therefore, workloads of the domain decomposition and the calculation of the physical optics integral are too heavy. In order to improve efficiencies, this letter proposes the multilevel second-order physical optics (MLSO-PO) method, which combines the quadratic discretization with the multilevel technology. The workload of the domain decomposition will be reduced greatly, since there has been a decrease in the number of patches. Furthermore, we implement closed-form formulas with the complementary error function to avoid highly oscillatory phenomena. Numerical experiments are provided to benchmark the efficiencies of the MLSO-PO method.

中文翻译：

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计算高频散射场的多级二阶物理光学方法

多级物理光学 (MLPO) 方法是从一系列频率和纵横角执行散射模式模拟的有效方法。然而，用于离散散射体表面的平面补丁的数量将随着频率的增加而增加。因此，域分解和物理光学积分计算的工作量太大。为了提高效率，本文提出了将二次离散化与多级技术相结合的多级二阶物理光学（MLSO-PO）方法。由于补丁数量减少，域分解的工作量将大大减少。此外，我们使用互补误差函数实现封闭式公式，以避免高度振荡现象。